Variations in plant characteristics and soil properties
Shrub encroachment had differential effects on above and below-ground ecosystem functions of semi-arid alpine steppes (Table S2). The cover of herbaceous tended to increase following shrub encroachment (Fig. 2a and Fig. 3). However, the encroachments of both Leguminosae and Non-Leguminosae shrubs had no significant impacts on plant height, species richness, above and below-ground biomass of herbaceous species (Fig. 2b−e and Fig. 3). The SOC, STN, and NO3−N contents rather than soil water content greatly increased following shrub encroachment (Fig. 2f−h and Fig. 3). The MBC and MBN contents significantly increased after encroached by non-Leguminosae shrub rather than by Leguminosae shrub (Fig. 2i−j and Fig. 3). However, the NH4+−N only significantly enhanced after Leguminosae shrub encroachment (Fig. 2j).